Print

Email

Rebuilding The Chrysler 2.7L

Chrysler introduced its all new 2.7L DOHC V6 engine in 1998. It was designed from scratch with an aluminum block and heads that were unique to this engine and unlike any of the earlier pieces found on the 3.5L SOHC motors.

By Doug Anderson

Page 1 of 3

It was rated at 200 HP and it was originally used as the base motor in the Intrepid and Concorde, but it's been the optional engine in the Stratus and Sebring since 2001 and it will be the standard engine in Chrysler's new 300 sedan that's coming out later this year.

So, while there are over a million and a half of these engines in service and they're still being built today, the 2.7L has been tweaked and tuned along the way, so there are just enough differences to cause some problems if you're not careful. There are two blocks and four heads along with two tensioners and two different cam sprockets plus a couple of other minor changes, so it's easy for a rebuilder to make a mistake that will cost him some money. With that in mind, let's take a look at the 2.7L engine and see what Chrysler has done to it since the beginning.

Blocks

There's only been one block casting used for the 2.7L, but there are two versions of it with one small, but important, difference.

1998-00: The original block that was used in the LH cars in '98 and '99 had a 4663611 casting number. It was an aluminum casting with cast iron liners and four powdered metal main caps that were crossbolted to the block. The 2.7L was installed "north-south" in the LH cars with the front of the block facing the front of the car.

  2001-'03: When the 2.7L engine was installed in the Stratus and Sebring cars in 2001, the block had to be modified to make it fit in the new "east-west," transverse application, so the back corner of the bell housing on the passenger side was relieved to  provide enough clearance for the starter on the cars that came with manual transmissions. All the blocks were modified beginning in 2001, but the LH cars didn't need the extra clearance for the starter, so you can still use the earlier block without this modification for the LH cars up through 2003. This is all pretty straightforward except that the casting number - 4663611 - is the same for both versions of the block, so rebuilders will have to look at each one to see if it's relieved before using it for a Stratus or Sebring.

Cranks

There's only been one crank used in the 2.7L motor, but it had a hole in the snout for a pin through 2002 and a slot for a key beginning in 2003. It's a steel forging with no identification number on it, so rebuilders will have to learn to recognize it by sight.

Rods

Chrysler has used only one rod in the 2.7L. It's a powdered-metal forging with a cracked cap. There's no identification number on it, either.

Pistons

There's really only been one piston used in this engine since '98. There are a few subtle differences between the early ones and late ones because Chrysler switched suppliers from KSG to Mahle in 2001, but they're virtually identical and completely interchangeable.

Heads

All of the 2.7L heads are DOHC, aluminum castings and they all look pretty similar, but that's misleading because there are four different versions with two for the right side and two for the left side.

1998-'99 Right Side: The 4663979 head casting was used on the passenger side in '98 and '99. It had a threaded hole in the side of the head, up close to the front, for the screw-in cover that held the primary chain tensioner in place. There were a few of the early castings that had a raised bolt boss on the front of the head for a bracket that supported the wiring harness, but Chrysler switched to a clip that was bolted to the rocker cover soon after production began, so the bolt boss was deleted.

2000-'03 Right Side: The 4663979AB casting replaced the original right hand head beginning in 2000. There were two differences:

1. The chain tensioner was held in place with a flanged cover that was bolted to the head, so the big hole wasn't threaded and there were two, small, threaded holes beside it for the cover.

2. There were two additional bolt bosses on the front corner, right above the hole for the chain tensioner, that were used for the power steering pump on the JR cars beginning in 2001.

1998-'99 Left Side: The left head used for the 1998-'99 LH cars was a 4663697 casting. It had two bolt bosses midway back on the side of the head, right below the rocker cover rail.

2000-'03 Left Side: The original driver's side head was replaced by the 4663697AB in 2000. There were two more bolt bosses added closer to the front of the head, so there were four of them right below the rocker rail on these later heads.

Although the heads with the extra bolt bosses came out in 2000, it appears that extra bolt holes weren't actually used until model year 2001 when the 2.7L engine was installed in the Sebring and Stratus and the alternator and power steering pump were bolted directly to the bolt bosses that were added to both heads.

Cams

This is a DOHC motor, so it has four cams, a right and left intake and a right and left exhaust. They're all hollow cams with pressed-on lobes and they each have an identification mark etched on the barrel between the fourth and fifth lobes that's coded by location.

Right hand intake: Both of the intake cams have an oblong pad with two bolt holes for the cam gear plus a sprocket for the short chain that drives the exhaust cam, but the right hand intake cam is 15-1/2? long, so it's 1-1/2? shorter than the left hand intake cam that's 17? long. The ID number for the right intake cam is 100xxxxx and the Chrysler part number is 4792062.

Left hand intake: The left intake cam looks like the right one with both the oblong pad and the chain sprocket, but it's 17? long and carries a 200xxxxx ID number and a 4792063 Chrysler part number.

Right hand exhaust: The right hand exhaust cam is 15-1/2? long, but it doesn't have the pad for the cam gear because it's driven by the chain that's connected to the intake cam. The right exhaust cam has 300xxxxx etched on it and is available from Chrysler under p/n 4792058.

Left hand exhaust: The left hand exhaust cam looks like the right exhaust cam, but it's 17˝ long, just like the left intake cam, and it has 400xxxxx etched on it. It's listed under p/n 4792059 in the Chrysler parts book.

Front Covers

There have been two front covers used on the 2.7L, depending on where the engine was installed.

• If it's in one of the LH cars including the Dodge Intrepid or Chrysler Concorde, it came with the 4663614AB/AC front cover that's flat-faced except for the two raised bolt bosses that are there for the pulleys that are used for the serpentine belt.

• If it's in one of the JR cars, including the Sebring or Stratus, the front cover has a raised pad that's located in the middle, toward the top of the cover. The torque axis mount that supports the engine for this transverse installation bolts on to the top of the pad. This cover has 4792604AA cast onto it.
 

Oil Pans

The 2.7L came with two different aluminum oil pans, too, one for the LH cars and one for the JR cars. 

• The oil pan for the LH cars was a 4663743AB casting that sloped up toward the back of the pan. There's a flat pad on the side of the pan, right behind the oil filter, that was drilled for the return line from the auxiliary oil cooler that was standard on the cars that had the autostick transmission or the police package.
 
• The pan used on the Sebring and Stratus JR cars was a 4792367AA casting. It had a flat bottom and a scalloped corner toward the back of the pan on the same side as the oil filter. The scallop was needed to make room for the exhaust system on the transverse engines. This pan has a flat pad right behind the oil filter, too, but it was never drilled for any of these applications.